The present invention relates generally to insertable and removable typewriter ribbon cartridges of the type disclosed in U.S. Pat. No. 3,643,777 entitled TYPEWRITER RIBBON CARTRIDGE granted on Feb. 22, 1972 and U.S. Pat. Application Ser. No. 150,946 filed June 9, 1971 entitled TYPEWRITER RIBBON CARTRIDGE both of which are assigned to the assignee of the instant application. The present invention cooperates with a typewriter mechanism that is clearly described in co-pending U.S. Patent Application entitled AUTOMATIC FUNCTION MECHANISM FOR TYPEWRITERS filed simultaneously with the instant application with Edwin J. Hurley as sole inventor and assigned to the same assignee. The invention in its broadest aspects is not restricted to this cartridge structure, but has been illustrated and described for explanatory purposes and could readily be adapted to other cartridge housings or any other typewriter ribbon holder. The term "cartridge" as used hereinafter is defined to include any form of ribbon holder or container irrespective of configuration and the manner of insertion into the typewriter. The ribbon cartridge of the present invention may include an error correction ribbon disposed therein whereby the correction ribbon is guided from the correction ribbon cartridge supply chamber along an integral ribbon guide arm that extends from the correction ribbon cartridge supply chamber to the typewriter print station. More specifically, the present invention is concerned with a ribbon cartridge construction that includes a pair of abutments thereon to engage a backspace coupled responsive member and an escapement coupled responsive member when the ribbon cartridge is inserted into the typewriter, thereby actuating the backspace mechanism to reposition the typewriter carriage to the previous print station and to disable the escapement mechanism to prevent further carriage movement. One of the many useful applications of the present invention resides in the provision of an error correction ribbon within the cartridge. The correction of errors in typewriters as disclosed in the prior art in general require a series of sequential manually manipulative operations so that the carriage of the typewriter may be backspaced a plurality of times to correct the error. For example, when an operator typed an erroneous character, it first became necessary to manually depress the backspace key, thereby actuating the backspace mechanism to reposition the typewriter carriage to the proper print station for making the correction. After the erroneous typed character is removed by striking over the character through the correction ribbon, the backspace key was again manually depressed to actuate the backspace mechanism a second time. The typewriter carriage is repositioned to the proper printing station a second time and then the correct character is typed. Therefore, a series of manually manipulative operations by the operator were necessary to correct an erroneously typed character. The end result of the foregoing disadvantages of the prior art is that typing speed is significantly reduced, total typing time is increased and the possibility of compounding the error by inadvertent multiple backspacing is increased.
The present invention as applied to error correction overcomes the obvious disadvantages of the prior art in that the manual manipulation required to actuate the backspace mechanism and reposition the typewriter carriage to the proper print station is accomplished automatically by inserting the ribbon cartridge.